#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>

using namespace std;

class Solution {
public:
    string makeGood(string s)
    {
        int count = 1;
        while (count--)
        {
            for (int i = 0; i < (int)s.size() - 1; i++)
            {
                if ((s[i] + 32 == s[i + 1] || s[i] - 32 == s[i + 1]))
                {
                    ++count;
                    s.erase(s.begin() + i);
                    s.erase(s.begin() + i);
                }
            }
        }
        return s;
    }
};

int main()
{
    Solution s;
    cout << s.makeGood("AaBbCc");
    return 0;
}